Various techniques can be used for visualizing data sets, including large multi-dimensional data sets (which contain multiple dimensions or attributes). Examples of techniques of visualizing data sets include graphs, bar charts, pixel bar charts (in which pixels represent corresponding transaction records and are assigned colors based on values of attributes), pie charts, and so forth.
When large data sets are visualized, especially large multi-dimensional data sets, manually finding similar patterns occurring somewhere in a data set can be difficult, time-consuming, and impractical.